The present invention relates generally to hydraulic systems, and more particularly to using a wattmeter in conjunction with a hydraulic pump unit to obtain electric power measurements for use by a controller to determine fluid flow parameters during a transient-state start-up operation and diagnostics derived therefrom.
Hydraulic systems such as hydraulic pump units are used in a wide range of applications. Fluid power supplies for hydraulic rams, hydraulically actuated valves and lift oil systems are a few examples in which hydraulic pump units are deployed. A typical hydraulic pump unit includes a motor driven pump that supplies pressurized hydraulic fluid from a tank to actuators via a control valve. Because a typical hydraulic pump unit can transmit high forces of highly pressurized hydraulic fluid it is often difficult to find flow instruments with a long life. Without accurate flow rate readings, the ability for determining hydraulic fluid parameters and performing diagnostics on these hydraulic pump units is impaired.